The present invention relates generally to new and novel improvements in electronic display systems. More particularly, the present invention relates to electronic display systems which are capable of displaying communication signal strength values on individual electronic display modules to assist in calibration and diagnostic activities in setting up and optimizing the operation of such electronic display systems.
Large retail stores often deal with several tens of thousands of different kinds of goods. In such stores, much attention is paid to the management and control of the inventory of goods and the displaying and labeling of the prices of the goods being sold. Accordingly, much effort is expended and careful attention is paid to managing and controlling the stock of goods and to labeling prices of products displayed on shelves or in showcases. Mistakes as to the labeling of the prices of goods could cause dissatisfaction to customers and damage the reputation of the store.
Therefore, it is desirable to correctly identify the prices of goods and minimize the number of pricing errors. Accordingly, electronic shelf display systems having multiple electronic display modules have been developed. Such electronic display systems are typically arranged such that light weight compact electronic display modules which display the product's price, along with other product information, are placed on display shelves or showcases in front of the displayed products. These types of electronic display systems typically allow the prices of products displayed in the electronic display portions of the electronic display modules to be changed when the prices are raised or lowered and/or when the arrangement of goods displayed on the display shelves or showcases are changed. It is advantageous in such electronic display systems to have electronic display modules which are capable of providing acknowledgment of the receipt of transmitted price changes, bedchecks, as well as other transmitted information, to help identify "lost" or broken electronic display modules.
In such electronic display systems, it becomes possible to reliably identify the correct prices of goods since changes in the prices of goods displayed on the electronic display portions of the electronic display modules are controlled and managed by a communications base system or some other processing control unit. If desired, other product information, for example, inventory or stocking information, product identification numbers or codes, and product volume or weight, could be displayed on the electronic display portions of the electronic display modules. In addition, electronic display systems in accordance with the present invention could be used in applications other than retail store environments, for example, in identifying inventory information in warehouses or distribution centers.
When setting up electronic display systems which utilize wireless communication to and from a communications base station, it is normally desirable to maximize the communication signal strength received from the electronic display modules. A communication signal strength below a certain threshold value may result in the message not being received from the appropriate electronic display module. The communication signal strength received from electronic display modules is dependent on several factors, including the number and position of transmitting antenna stations, the configuration and set-up of the building and its contents, the number and placement of fluorescent lighting fixtures and refrigeration units and many others. Because so many factors influence the strength of the communication signal received from individual electronic display modules, it is often desirable to optimize the communication signal strength received from individual electronic display modules by "trial and error" or by observing the communication signal strength received from an electronic display module under certain operating conditions, changing the operating conditions in some controlled manner, and observing the effect on the communication signal strength received from the electronic display module.
In the past, a relatively sophisticated and expensive piece of equipment, for example a signal spectrum analyzer, was typically used to measure the communication signal strength at individual electronic display modules. Using such a separate piece of test equipment is disadvantageous in not only the cost, but also in that a separate piece of test equipment must be carried to and from each individual electronic display module. In addition, a source of electrical power, such as a battery or electrical cord and outlet, is generally required to provide electricity for operation of such a separate piece of test equipment. Furthermore, using such a separate piece of test equipment may be cumbersome in certain locations, such as in freezers or other compact areas.
Moreover, a signal spectrum analyzer or power meter can only measure the radio frequency signal strength at the electronic display module's location. The acknowledgment signal strength results from the two paths from the base communications station down to the individual electronic display module and a reflection of the signal from the electronic display module back up to the base communications station. The loss experienced during this two-way radio frequency signal path can be readily and accurately measured in accordance with the teachings of the present invention. Namely, by using the actual installed base communications station, including its own antennas, and actual electronic display modules, the loss experienced during two-way radio frequency signal transmission is measured and displayed on the electronic displays of the particular electronic display modules of interest.
Accordingly, an object of the present invention is to provide an electronic display system which is capable of measuring the communication signal strength received from individual electronic display modules.
Another object of the present invention is the provision of an electronic display system having electronic display modules which are capable of displaying a value representing the communication signal strength received from the individual electronic display modules.
These and other objects of the present invention are attained by the provision of an electronic display system having electronic display modules which are capable of displaying a value representing the communication signal strength received from the individual electronic display modules. In one preferred embodiment of the present invention, a pseudo-price change command is transmitted by a base communication station to an individual electronic display module and the strength of the acknowledgment signal received by the base communication station is temporarily stored. The base communication station then transmits a command to change the electronic display on that particular electronic display module to display the value of the received communication signal strength.
Other objects, advantages and novel features of the present invention will become apparent in the following detailed description of the invention when considered in conjunction with the accompanying drawings.